Starter had second thoughts....

Unit74

Unit74

Final Approach
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Unit74
It was in the mid 30s last night. Pulled the plane out of the hangar and attempted to start it. Turned key and prop moved about a foot and nothing. Waited about 10 seconds, tried again, same thing. Waited 10 seconds and it turned over just fine, fire up and after 10 seconds agreed to run smooth.

This is the second time this has happened. Last time it was cold as well. Plane was flown a week ago.

Stats:

Tio540
Hartzell E series starter and Concord 35 AXC both have 20 hours since new. Plane flies weekly.

Basically, turned the key and the starter acted like there was no ump at all. Anyone know what’s up? Is this just a case of cold AM woes or something more serious?
 
That's a big motor and a lot of piston to move. Preheat is your friend and the battery loses capacity as it gets colder.
 
Unit74 said:
It was in the mid 30s last night.
Basically, turned the key and the starter acted like there was no ump at all. Anyone know what’s up? Is this just a case of cold AM woes or something more serious?
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This is why we pre-heat.
 
Does it only happen during the winter months or does it occur year-round?
 
It’s happened twice when it’s cold. New starter and battery. I normally would preheat but I had a pop up flight this AM....
 
In the cold, some people turn on their car headlights and then off before starting their cars. This sort of wakes up the battery and gets electrons flowing. The first two starting attempts may have done the same thing. Next week, turn on the landing lights for a few seconds to excite the battery and see if it starts.
 
cgrab said:
In the cold, some people turn on their car headlights and then off before starting their cars. This sort of wakes up the battery and gets electrons flowing. The first two starting attempts may have done the same thing. Next week, turn on the landing lights for a few seconds to excite the battery and see if it starts.
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Those dam lazy electrons!
 
OP, are you using a multi-grade engine oil? If not, you might want to switch at least during the winter.
 
Mid 30s with a new starter and battery and multi-grade oil? That shouldn't be that hard to start... Course mine is a measly 180hp...
 
I had a Cherokee that would do that. Rather than hold the starter button against the resistance, I'd release it and "catch the bounce" as the prop bounced back toward the right off the compression stroke. Worked pretty good, and much easier on the starter.
 
cgrab said:
In the cold, some people turn on their car headlights and then off before starting their cars. This sort of wakes up the battery and gets electrons flowing. The first two starting attempts may have done the same thing. Next week, turn on the landing lights for a few seconds to excite the battery and see if it starts.
Click to expand...
The current flow warms the battery, and the chemical reactions in a warm battery happen faster than in a cold battery. Faster reactions means larger electron flow. The initial start attempt draws hundreds of amps and will warm that battery.
 
Clip4 said:
Your issue is a bad connection or wire.
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Could be any of dozens of things. If it happens in the warmer weather I'd be measuring voltage drops across contactors first of all. Old contactors in old airplanes are almost guaranteed to have burnt and oxidized contacts in those contactors. Battery manufacturers love old airplanes because they sell a lot of batteries due to tired contactors.
 
Even a quick preheat would be better than none... I'm a preheat freak... I use a sump heater but have a rigged up electric space heater and duct just in event a pop up flight occurs and I don't have in plugged in. Hooking that up and a cup of coffee would be better than firing her up ice cold... Bearings in the cold can get incredibly tight, from my understanding well BELOW tolerances of even a brand new engine... Probably not completely it or the third time may not have done the trick, but sure probably contributed to the difficulty... Preheating is not really about the oil if we are using multi viscosity...
 
I’m a preheat freak too. Just couldn’t crank below 40 or so without some time plugged in. I like at least 5 hours, usually overnight. I throw a blanket on the cowl too.
 
sourdough44 said:
I’m a preheat freak too. Just couldn’t crank below 40 or so without some time plugged in. I like at least 5 hours, usually overnight. I throw a blanket on the cowl too.
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I agree with all that. I wrap the prop and spinner up too with pillow cases... An overhaul is almost the value of my plane even in it was restored to perfection inside and out, so I want to keep that day as far away as possible... Some say I may be overly worried about it, maybe I am but idc if I am... Pop up flights concerned me as I've elected to not leave it plugged in 24/7 which is why I rigged the electric heater up for in a pinch... If I notice that happening much I will just switch to 24/7 all wrapped up.
 
It’s your oil. Preheat should remedy the issue.

PM me your number or email and I’ll send a video demonstration of cold 20-50XC that I captured on my phone at Oshkosh last year.

EDIT: I remembered wrong, it was a series of Live Photo’s on my iPhone, not vids. See one pic below. One oil type on the left clean and dirty, another on the right clean and dirty. The oils were in a test tube chilled at some temperature, and the demonstration tilted all 4 test tubes at the same time to view the flowability.

(POA gang: Please don’t turn this thread into a fight about oil...Cumulofeces. Just preheat regardless of brand).

03AAB8DA-0368-4841-AB25-6EC294BFD6AA.jpeg
 
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455 Bravo Uniform said:
It’s your oil.
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I don't believe oil in the mid 30s would prevent the engine from turning over at all.

A worn ignition switch, a bad starter solenoid, or a faulty wiring connection between the two is where I would start looking.
 
Chip Sylverne said:
I had a Cherokee that would do that. Rather than hold the starter button against the resistance, I'd release it and "catch the bounce" as the prop bounced back toward the right off the compression stroke. Worked pretty good, and much easier on the starter.
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The problem with that is if you engage the starter at the wrong time, you risk chipping a tooth on the fly wheel. Rare, but it can happen if the starter tries to engage while the fly wheel is in motion.
 
Dan Thomas said:
The current flow warms the battery, and the chemical reactions in a warm battery happen faster than in a cold battery. Faster reactions means larger electron flow. The initial start attempt draws hundreds of amps and will warm that battery.
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This is going to be a very large part of it, if not all of it. The starter itself will be a little less powerful when current warms it up, but the first two attempts really warms up the battery, so the increased battery temperature allows for much more current out of the battery.
 
3393RP said:
I don't believe oil in the mid 30s would prevent the engine from turning over at all.

A worn ignition switch, a bad starter solenoid, or a faulty wiring connection between the two is where I would start looking.
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If the ignition switch was bad the starter contactor wouldn't even engage and there'd be no action at all.

Both the starter and master contactors are in the circuit and should be checked if the problem continues into warmer weather.
 
Starter may need an overhaul with new brushes and commutator undercutting. Or it could be wiring & component resistances.

Measure the voltage delivered to the starter - at the starter.
 
nrpetersen said:
Starter may need an overhaul with new brushes and commutator undercutting. Or it could be wiring & component resistances.

Measure the voltage delivered to the starter - at the starter.
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Problem is, few shops are doing that anymore. their attitude is just get a new one.
 
I've seen pilots pull their prop thru several blades, then leave it just after compression stroke, so it will get half a stroke prior to coming up on compression.
 
Dan Thomas said:
If the ignition switch was bad the starter contactor wouldn't even engage and there'd be no action at all.

Both the starter and master contactors are in the circuit and should be checked if the problem continues into warmer weather.
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I've seen instances where the start contacts in the ignition switch failed to close intermittently, but it's uncommon. The start and master solenoids are more likely to be the problem, as you said.
 
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nrpetersen said:
Starter may need an overhaul with new brushes and commutator undercutting.
Click to expand...

Post #1:

Hartzell E series starter and Concord 35 AXC both have 20 hours since new. Plane flies weekly.
 
455 Bravo Uniform said:
It’s your oil. Preheat should remedy the issue.

PM me your number or email and I’ll send a video demonstration of cold 20-50XC that I captured on my phone at Oshkosh last year.

EDIT: I remembered wrong, it was a series of Live Photo’s on my iPhone, not vids. See one pic below. One oil type on the left clean and dirty, another on the right clean and dirty. The oils were in a test tube chilled at some temperature, and the demonstration tilted all 4 test tubes at the same time to view the flowability.

(POA gang: Please don’t turn this thread into a fight about oil...Cumulofeces. Just preheat regardless of brand).

View attachment 70822
Click to expand...
I'm curious, which aeroshell was he using for the demo?
 
Huckster79 said:
Even a quick preheat would be better than none...
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Not necessarily true. Depends on the pre-heater you have. If you have a red dragon or torpedo style heater, some of the engine will be very hot and some will still be ice cold, like holding a torch to a frozen chicken pot pie. This wreaks havoc with the engine clearances and would be far, far worse than just starting cold.

See this thread:
https://www.pilotsofamerica.com/com...ds-how-to-make-your-engine-last-ground.55073/
 
Sometimes I like to [carefully] pull the prop through by hand a few times.
 
Mtns2Skies said:
Not necessarily true. Depends on the pre-heater you have. If you have a red dragon or torpedo style heater, some of the engine will be very hot and some will still be ice cold, like holding a torch to a frozen chicken pot pie. This wreaks havoc with the engine clearances and would be far, far worse than just starting cold.

See this thread:
https://www.pilotsofamerica.com/com...ds-how-to-make-your-engine-last-ground.55073/
Click to expand...

Excellent point. Poor wording on my part in terms of what i meant, I meant in terms of just getting it started not careful babying of the engine. Quick to me is hour or so plugged in with electric space heater ducted in too with cowl all covered. My normal would be a good 6 to 8 hours plugged in and cowl wrapped tight. I concur that quick blast and go is hell to long term care and preach against. I love pulling the blanket off and finding cylinder heads warm to the touch... :)
 
Marc J Woods said:
Is there a way to test for this? Resistance perhaps?
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It's been discussed here in numerous threads.

Measuring resistance would only work if you had an ohhmeter that could measure tiny fractions of an ohm. A circuit that has large current flow, like the starter circuit that can easily run 250 amps or more, will create large voltage drops across tiny resistances. Ohm's Law says that E=I x R; voltage is equal to current times resistance. A resistance of .05 ohms (1/20th ohm) for instance, with 200 amps going through it, will create a 10-volt drop across that resistance. That theoretically would leave only two volts for the starter. Of course, that big voltage drop also reduces the current flow as well, so if we assumed that there was only 100 amps left running through the circuit, we'd still get a five-volt drop through that small resistance, and the starter would respond pretty sluggishly.

Tiny resistances matter. Dirty or corroded connections in numerous possible places between the battery and starter and in the ground return path. One of the more common is the burned and oxidized contacts in the contactors (solenoids). One can isolate the voltage drops by using a voltmeter across the various places and measuring the actual voltage drop while the starter is cranking. Much easier than trying to measure tiny resistances.
 
Dan Thomas said:
It's been discussed here in numerous threads.

Measuring resistance would only work if you had an ohhmeter that could measure tiny fractions of an ohm. A circuit that has large current flow, like the starter circuit that can easily run 250 amps or more, will create large voltage drops across tiny resistances. Ohm's Law says that E=I x R; voltage is equal to current times resistance. A resistance of .05 ohms (1/20th ohm) for instance, with 200 amps going through it, will create a 10-volt drop across that resistance. That theoretically would leave only two volts for the starter. Of course, that big voltage drop also reduces the current flow as well, so if we assumed that there was only 100 amps left running through the circuit, we'd still get a five-volt drop through that small resistance, and the starter would respond pretty sluggishly.

Tiny resistances matter. Dirty or corroded connections in numerous possible places between the battery and starter and in the ground return path. One of the more common is the burned and oxidized contacts in the contactors (solenoids). One can isolate the voltage drops by using a voltmeter across the various places and measuring the actual voltage drop while the starter is cranking. Much easier than trying to measure tiny resistances.
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Thank you Dan.
 
I had a similar problem in the cold morning (35F) on Sunday. Mine seemed to barely turn over the engine to start. I noticed after I checked the lights (all of them and includes wing tip recognition lights) maybe 30 seconds and prior to starting the engine, that my batter only showed 11.6 volts. This after having it plugged in to a maintainer for a week. Is this normal voltage drop?
 
Are you saying it showed 11.6 with all the lights on, or was it after they we're turned off?

With the lights on, the voltage should still be about 12.4.

Something isn't right.

I would remove the battery, bench charge it in a warm environment, and perform a capacity test, even if it's just a clamp on resistive tester.
 
A battery showing 11.6 volts open circuit is about 25% charged. As I said above, remove it and connect to a charger capable of at least 10 amps output. Charge it 20 hours and the open circuit voltage should be around 12.7.

Voltage should be around 11.9-12.1 when cranking the engine.
 
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